The scoring is telling. Clearly the problem was not isolated to one bore. So either it lost oil pressure at some stage of its life (I think you would have simply lost compression or started burning oil in that event) or something about wvo fried or stuck the rings. I have seen an om617 at the shop being rebuilt after being run on wvo. All varnished up on the inside. I think the problem has to do with all sorts of other organic stuff in the fuel which accumulates over time. And a general lack of quality control on the fuel between sources making it hard to compare impact on motor life. I think you did the right thing rebuilding it. I would have done the same as the cost is maybe 3k more to have a totally fresh motor vs unknown quantity. Maybe put some forged rods in while it's apart ;-)

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